Abstract

A Nyaya definition the major purpose of which is efficient use of words and avoiding ambiguities and errors, is the statement of a unique feature that belongs to each definiendum and nothing else so that there is none of the three faults of overcoverage, undercoverage and failure to belong to any definiendum. There should be no circularity that is of three kinds, self-dependence (where the definiendum appears in the definiens); mutual dependence (where the definiendum and the definiens are used in the definition of each other) and defining in a circle. A definition should also be economical: there are mainly three kinds of economy; economy in constitution (that avoids including anything superfluous or unnecessary to distinguish the definiendum from everything else), economy in relation (the directly related is preferable to the indirectly related) and economy in cognition (something cognitively prior is preferable to something posterior). While more than one definition is possible that need not state the essence, the test of economy is in place to avoid redundancy and provide criteria of preference among defining features that are unique and non-circular.